No they won't... I tried... The springs will fit in some heads but not in others (depending on how they bored the spring walls, I have one 95 head that they wouldn't fit in, rubbed on the wall, and one 98 head that they would). The other problem is the retainers, you can't use the stock ls retainers due to the fact that there is no step for the inner spring and your stock ls keepers wont fit in the b16 retainers.
edit: Oh yeah, and don't use the b16 inners with the stock ls outers, they will bind (found that out the hard way, put in the cam, turned it over, springs went down but not back up)